Mycoplasma

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12/30/01

Mycoplasmas are slow-growing micro-organisms, members
of the mollicute family, and are characterized as virus-like infectious
agents, somewhere between a virus and bacteria. They lack the normal
rigid peptidoglycan cell wall of bacteria, which allows them to invade
all the tissues and organs of the body, including the brain, causing
complex symptoms. There are hundreds of different mycoplasma subtypes
and strains.

The two most common isolation sites in humans are
respiratory and genito-urinary tracts, although isolation from synovial
fluid and other anatomical sites have been reported. Mycoplasma are
currently under intense study as being at least a cofactor in the
causation of AIDS, Fibromyalgia Syndrome (FMS), Gulf War Illness (GWI),
Rheumatoid Arthritis (RA), and Chronic Fatigue Syndrome (CFS).

Mycoplasmas are known to cause serious and often fatal
illness in goats. These are caused by several different subtypes and
strains. These include M. capricolum subsp capripneumoniae,
M. capricolum subsp capricolum, M. conjunctivae, M. mycoides subsp.
capri, M. mycoides subsp. mycoides LC, M. putrefaciens, M. yeatsii, A.
oculi. For those who like to surf for pictures, the following
links to some of the more common types are provided:

A test for detecting Mycoplasma in the blood, known as the
polymerase chain reaction (PCR) has been developed, but it may not be
available through all labs at this time. Although they have probably
been around for a long time, mycoplasma infections appear to be on the
increase in goat herds and will certainly be receiving increased
scrutiny in the future.

This disease appears to be increasing in frequency among adult and baby
goats around the world. It is extremely contagious and results in a
very high percentage of deaths in a herd. First signs are cough,
shortness of breath, runny nose, loss of appetite and severe
weakness. It can be accompanied by a high fever, with the head lowered
and/or extended and an arched back. Since the causative agents can also
be found in cases of mastitis and abortion, it is indeed possible that
the disease can be transmitted from an infected dam; although it is
generally presumed to be spread via aerosol droplets. Likewise, another
of the symptoms that can accompany CCP is arthritis, but this will be
discussed below. There are some forms of the disease which show no
respiratory signs, but merely weakness and a high fever (septicemia,
see below).

Arthritis (polyarthritis)

M. agalactiae, M. capricolum, M.
mycoides

This is the situation most likely to be seen by goat herders. Healthy
young kids will suddenly start
limping, hunch their backs, stop eating, go down crying in obvious pain
and die within a few hours. Blindness has also been reported. In some
instances, the mothers will be obvious cases of mycoplasma mastitis
(see below), but the link is not always guaranteed. The diagnosis must
be differentiated from enterotoxemias of Clostridium
perfringens C and D and "navel ill."

Mastitis ("Contagious Caprine Agalactia")

M. agalactiae, M. capricolum, M.
mycoides, M. putrefaciens

This topic has been covered at our page on mastitis.
The dam will show the signs of mastitis discussed there (with the odor
of putrification if caused by M. putrifaciens), but
the kids may show any or all of the mycoplasmal symptoms of pneumonia,
arthritis, conjunctivitis (with yellow discharge), septicemia, fever,
weakness, etc. leading to a very high mortality rate.

Conjunctivitis (Infection of the lining of the eye)

M. agalactiae, M. conjunctivae, M.
mycoides

It will be practically impossible to tell this type of conjunctivitis
from the many other common types, unless it occurs with some of the
mycoplasmal symptoms mentioned above. We have had some people report a
yellow discharge in cases where this disease has been suspected, but
this does not have scientific support.

Septicemia

M. capricolum, M. mycoides, M strain
F38

This is a really serious perdicament wherein the infection has more or
less penetrated throughout the entire body. It frequently results in
rapid death and will resemble the situation discribed under arthritis
above. It can probalby be the end result of any of the above.

Treatment

There are some sources which recommend the strict culling of
all cases of mycoplasma infection due to the fact that successful
treatment may result in the creation of carriers which can later infect
new additions to the herd or someone else's animals if the carriers are
sold. This may be a matter of personal choice and we do not have enough
information to judge the validity of these claims.

If there is going to be any success at all, treatment must
be immediate and vigorous. All showing any of the
above signs should be isolated at once. All members of the herd should
be started on a course of antibiotics. Most authorities recommend the
use of tylosin (Tylan200®) IM for 3 or 4 days. Others have had
success with high doses of tetracyclines such as LA200®. (We
would choose the Tylan®.) There is some evidence that
penicillin may do more harm than good. We STRONGLY suggest that you
follow the advice of your veterinarian.

Supportive therapy is also important. If the mother has any
signs of mastitis (or any of the other mycoplasmal symptoms), the kids
should either be bottle fed off other dams or her milk should be
pasteurized.

There is currently some speculation as to the transmission
of mycoplasmas to humans. Although there is increased attention to
possible human disease implications, there has not been enough solid
evidence that we know of to justify the classification of mycoplasma as
a true zoontic disease. None of the subtypes discussed above have been
mentioned as being present in human patients that we know of. But more
research in this area is certainly in order and will probably be
undertaken in the future. Milk taken from an infected doe would best be
disposed of and normal precautionary measures such as milking known
sick animals last should always be followed.

Comments

In preparing for this page, I have been deeply fascinated by
this topic. It is one which shall certainly hold a lot of interest for
veterinary (and human medical) researchers in the near future. There
are obviously an awful lot of blank pages to fill in. In our "Symptoms
pages" (goatwisdom/alpha/a - z) you will notice the Heidi Disease
listed quite frequently. This is a disease which went through some of
the kids in our herd a few years back. I was never able to make a
definite diagnosis, but in preparing for this page, I have an inkling
that it may have been the result of one of the types of mycoplasma.

There seems to be a real shortage of "down and dirty"
information about this topic. If anyone has first-hand experience with
this disease or the symptoms outlined above, we would be most eager to
hear from you.